1. Field of the Invention
The present invention relates generally to cable adaptors for interfacing and configuring signal-carrying conductors linking two pieces of electrical equipment, and more specifically to a programmable adaptor using pre-configured keys to selectively configure signal paths from one connector having a first pin configuration to another connector having a second pin configuration to allow communication between two pieces of electrical equipment, such as an on-board automobile computer and a piece of diagnostic equipment.
2. Brief Description of the Prior Art
The standard in modern automobiles is to have a computer or number of computers on-board the automobile to manage and control the various systems within the vehicle. For example, through the use of an oxygen sensor in the exhaust manifold, the computer can detect how efficient the fuel is being consumed by the engine and adjust the rate of fuel injection accordingly. In addition, the computer can monitor the electrical demand and regulate the output of the alternator, etc.
In the shop, each on-board computer can be connected to a piece of diagnostic equipment via cables and connectors, and the integrity of the system can be checked to ensure that it is functioning properly. In addition, the diagnostic equipment can receive signals indicating error codes generated by the computer indicating past or presently occurring events. The diagnostic equipment can also send signals to the computer to have the computer initiate certain activity to test the various systems of the automobile.
The need for the present invention stems from the fact that although on-board computers may use the same types of plugs, jacks or other connectors used to interface with the diagnostic equipment, the pin assignments for the signals may be different from one type of computer system to another automotive vehicle or for each computer on board the vehicle. For example, a connector typically used by on-board computers is the J1962, which has 16 contactor pins within the connector for communications, voltage measurements and control functions. Different on-board computer systems may use these 16 pins differently. For example, one vehicle computer system may use pin number 5 to transmit engine data, pin number 6 to transmit transmission data, and pin number 7 to provide an external control of the EGR solenoid valve, while another vehicle computer system may use pin number 5 to transmit air bag data, pin number 6 to transmit engine data and pin 7 to provide an oxygen sensor voltage measurement. Because of the variations in the configuration of pin assignments, it is sometimes difficult or confusing to use diagnostic equipment to properly recognize and process signals.
Before the present invention, a different adaptor was usually provided for each different combination of pin configurations. The major problem with having a separate adaptor for each different pin configuration is cost. It is expensive to manufacture a set of adaptors for every model year with new pin configurations to interface with new computer systems.
One alternative solution might be to connect input signal pins to output signal pins via wires and allegator clips. But such method would be tedious, impractical, and mistake-prone. Another alternative might be to provide a multiplexer within the diagnostic equipment to configure the signal paths. The problem here is that such method increases the complexity and cost of the diagnostic equipment, since every possible combination of signal routine must be accounted for.
Although no automotive related solutions to the problems mentioned above are known, approaches remotely related to the present invention have been provided in other fields. For example, in U.S. Pat. No. 5,130,893, Straate discloses a system for distributing input signal-carrying lines to selected output lines. More particularly, he provides a signal distribution system for distributing input telephone and cable TV lines to appropriate locations in a facility. This signal distribution system is a routing scheme where a multi-conductor cable, such as a telephone line, is selectively routed to multiple locations in a facility while another telephone line may be routed to other locations within or without the same facility. This system may be distinguished from the present invention because it does not reconfigure connections between the conductors of two different multiwire cables, but instead simply connects one or more input cables of a particular type to one or more output cables of the same type.
A need thus exists for an easy-to-use and low-cost apparatus to properly configure signal-conducting paths from one device to another device.